This invention relates to an improved clamping assembly designed to attach a magnetically operated electrical switch to a tie rod and against the outside surface of a pneumatic cylinder in such a way that the piston within the cylinder will appropriately interact with the switch.
The invention further relates to a clamping assembly which is useful with cylinders having a wide range of diameters thereby eliminating the need to have multiple clamp assemblies available for use depending upon the particular size of the cylinder with which the switch is to be used.
Fluid operated or pneumatic cylinders are controlled by various sensors and switches designed to sense the position of a reciprocating piston within the cylinder. Thus, a cylinder generally includes a cylindrical shaped tube with a piston reciprocally mounted therein. The tube is typically surrounded by tie rods which connect and hold caps or heads at the opposite ends of the tube. A sensor or electrical switch is mounted at a position along the tie rod of the cylinder to sense the piston as its passes the sensor. The piston typically will include a magnet that actuates a reed switch, for example, associated with the sensor.
Heretofore various types of mounting systems have been available for attaching such a magnetically operated sensor to a cylinder tie rod. For example, Thomas White, Ltd. of England manufactures a two part clamp assembly which fits under the tie rod adjacent to the cylinder. A connecting band between the two clamp parts is adjustable depending upon the size of the cylinder.
Canfield Industries of Youngstown, Ohio has sold another two part clamp which includes a hook member that fits over the tie rod. The hook thus holds the switch against the side of the cylinders.
These prior art constructions have various problems. For example, the Canfield product may slip or pivot in an undesirable fashion on the tie rod. Also, the Canfield product may not be useful for cylinders of varying size. The Thomas White product may not fit through the space between the tie rod and the cylinder wall of a cylinder and it may not fit with the desired sensor. Thus, there has remained a need for an improved clamp assembly for securing apparatus to a tie rod for holding a switch against the outside surface of a cylinder.